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This week EE Times will feature updates on some of the carbon-reducing technologies being developed or already in use that could help companies, countries and citizens reduce their carbon footprint. These are some examples to show the infinite variety and to give credit to engineers and companies working on them.

There is little doubt that the climate is heating up (see NASA GISS chart below) and that it is due to the production of greens-house gases, which have been steadily increasing since the maturation of the industrial revolution circa 1880, according to The Intergovernmental Panel on Climate Change (IPCC 2015) meeting this week in Paris at the Conference of the Parties (COP21, Nov. 30–Dec. 11).

Last year the IPCC declared that scientists were 95 percent certain that global warming is being caused (mostly) by increasing concentrations of man-made greenhouse gases—carbon dioxide, methane and nitrous oxide—most of which is being produced by electrical power plants and internal combustion engines.

Carbon-free sustainable electrical power generation has been accomplished with power-generating river dams since the invention of the electrical generator, but in many places the dams are being disassembled because of the negative impact they have had on fish runs. No matter. We now have even cleaner methods of electrical power generation.

Solar cells
The most promising zero-carbon electrical power generators are solar cells, which already come in all sorts of formulations, sizes and capacities.

According to the U.S. Department of Energy, every hour, enough energy from the sun reaches Earth to meet the world’s energy usage for an entire year. Of course its impossible to cover the lighted half of the 198 million square miles of the Earth’s surface in solar cells. Even collecting all 365 days of the year with widely distributed solar cell arrays illuminated half the day (12/7) at 20 percent efficiency would take over 225 thousand square miles to satisfy the entire world’s need for energy—a seemingly unachievable goal.

However, that is not stopping the world’s scientists from trying. One of the latest attempts comes from multi-band solar cells

More than one third of Germany’s 21,500 wind turbines are located in the nation’s east. This concentration of generating capacity regularly overloads the region’s electricity grid, threatening blackouts.

German Economics Minister Rainer Brüderle recently warned that Germany faces frequent power blackouts because too much ‘green electricity’ is being pumped onto the grid.

While this is a problem all four of Germany’s major electricity network operators have to deal with one time or another, Belgian-Australian company 50Hertz Transmission is particularly hard hit. It took over the monitoring and protection of the eastern German energy grid – which is home to more than 8,000 wind turbines – from Swedish company Vattenfall last year, and faces the threat of power outages much more often than its counterparts.

In 2006, when wind farms were few and far between, coal, gas and nuclear power plants produced just the amount of energy needed in eastern Germany at the time, but also created large amounts of nuclear waste and carbon dioxide emissions. The system was relatively stable. One average, engineers took action to stabilize the eastern German grid roughly 80 times a year.

Today, as the amount of electricity generated by the region’s 8,000 wind turbines rises and falls by the hour, engineers have to intervene every second day to maintain network stability.

The Global Wind Energy Council (GWEC) reports that in 2010, about 40 percent of Germany’s wind power production – or 6 percent of global output – came from eastern Germany. That figure is expected to rise dramatically as “Baltic 1,” a gigantic new offshore wind park in the Baltic Sea, enters operation later this month. Another 13 projects are planned for the next few years.

Electricity ‘export highways’

With no technical means of storing this surplus energy, 50Hertz safeguards the eastern German grid by managing production levels and exporting electricity to other regions.

In 2009, exports to western Germany, neighboring Poland and the Czech Republic reached 6.5 gigawatts on days with strong winds. As more new wind farms go online, Erbring said, exports are bound to increase even further.

“We will then have to transport 80 percent more from our control area than we did in 2009,”

In theory, the control center at 50Hertz can order individual wind farms taken off the grid during strong wind phases. But in reality, that is a rare exception as 50Hertz is bound by German energy laws that stipulate that “green” power must always have priority on the grid.

As a result, coal, gas and nuclear facilities should be shut down before wind turbines are taken offline, but operators say they avoid this because they rely on traditional power plants to produce a consistent level of base power at all times.

50Hertz security expert Hans-Peter Erbring warned it’s a tense situation: “Eastern Germany will continue to have major grid stability problems if the links aren’t in place within the next few years.”